Shear cell tests for quantification of tailings segregation

Talmon, A.M.; Kesteren, W.G.M. van; Sittoni, Luca; Hedblom, Eric

doi:10.1002/cjce.21856

Cited by 11 publications

(4 citation statements)

References 21 publications

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“…The chemical and mineralogical variability could be explained based on two parameters, which are: (i) The heterogeneity of tailings' physical characteristics (particle size distribution and specific surface area) caused by tailings segregation during their deposition [64], and (ii) the initial heterogeneity of the mineralogical characteristics of the ore body. Moreover, oxidized tailings and hardpans samples showed a relatively similar mineralogical composition regarding secondary minerals contents, but a different texture.…”

Section: Discussionmentioning

confidence: 99%

Spatial Mapping of Acidity and Geochemical Properties of Oxidized Tailings within the Former Eagle/Telbel Mine Site

et al. 2019

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At some orphaned and abandoned mine sites, acid mine drainage can represent a complex challenge due to the advanced tailings' oxidation state as well as the combination of other factors. At the field scale, several parameters control sulfides' oxidation rates and, therefore, the acidity generation. The objective of this paper is to map the acidity and geochemical properties of oxidized tailings within a closed tailings storage facility. Based on systematic sampling, various geochemical parameters were measured within the oxidized Joutel tailings, including the: Neutralization potential, acid-generating potential, net neutralization potential, neutralization potential ratio, paste pH, thickness of oxidized, hardpan, and transition zones. The different parameters were integrated in geographical information system (GISs) databases to quantify the spatial variability of the acidity and geochemical properties of oxidized tailings. The oxidized tailings were characterized by low sulfide (mainly as pyrite) and carbonate (mainly as siderite/ankerite) contents compared to unweathered tailings. Acidic zones, identified based on paste pH, were located in the eastern portion of the southern zone and at the northern tip of the northern zone.Minerals 2019, 9, 180 2 of 23 released [9][10][11]. This phenomenon is known as acid mine drainage (AMD) or acid rock drainage (ARD). In some cases, drainage waters can be near-neutral in pH and still contain concentrations of elements that surpass environmental standards and regulations. This phenomenon is known as contaminated neutral drainage (CND) [12] or metal leaching (ML). The cost of mine site reclamation is influenced by the type and quality of drainages produced in TSFs [13].The process of sulfide oxidation can result in the generation of protons. This increases the acidity of pore waters and leads to the dissolution of carbonates, which buffer the acid. Depending on the geochemical conditions in the pore water, various reactions may occur, such as: Hydrolysis, precipitation,. During these reactions, the tailings' mineralogical composition can change significantly depending on the dissolution rates of sulfides, carbonates, and, to a lesser extent, silicates. As a result of oxidation, neutralization, and hydrolysis reactions, novel phases may precipitate. The most common secondary phases are ferric oxyhydroxides (e.g., goethite, ferrihydrite, lepidocrocite), gypsum, and iron sulfates. These secondary phases affect the geochemical behavior of tailings considerably [10].Ferric oxyhydroxides are known for their high affinity to limiting contaminant mobility through mechanisms, including co-precipitation, adsorption, and substitution. Under some specific conditions, the occurrence of secondary phases may also affect the hydrogeochemical behavior in TSFs by modifying the tailings' hydrogeological properties, such as porosity. For example, the formation of hardpan within TSFs affects the water balance and flow paths [18,19]. Hardpan formation is more likely to occur at orphaned or aban...

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Section: Discussionmentioning

confidence: 99%

Spatial Mapping of Acidity and Geochemical Properties of Oxidized Tailings within the Former Eagle/Telbel Mine Site

et al. 2019

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“…Settling of particles in shear, whereas they do not settle at rest, is a known phenomenon, quantified for single particles by Thomas (1979), Wilson and Horsley (2004), Talmon and Mastbergen (2004) and Pullum et al (2010), and for multiple particles settling simultaneously (Cooke 2002;Pirouz et al 2008;Talmon et al 2014a;Ovarlez et al 2012). Solids settling in shear flow is called shear settling or dynamic settling.…”

Section: Figure 1 Changing Properties Of Sand-carrier Mixtures By Difmentioning

confidence: 99%

Shear settling in laminar open channel flow: analytical solution, measurements and numerical simulation

Talmon¹,

Sittoni²,

Shahmirzadi³

et al. 2018

Proceedings of the 21st International Seminar on Paste and Thickened Tailings

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In beaching of tailings, sand and clays may segregate. In laminar flow this is due to shear settling. First implementations of shear settling in numerical flow models are seen, offering unprecedented potential to conduct tailings management studies. In order to validate numerical codes, reference materials are necessary. For laminar flow, there is a small set of flume tests available from an earlier study. An analytical solution for transient sand concentration profile development with distance in laminar open channel flow appeared recently. This analytical method is more complete than an analytical model developed earlier at the author's institute. Data and analytical solutions are analysed and applied to serve for the validation of numerical flow simulation of beaching in tailings storage facilities. Fair agreement is observed between measurements and the analytical method. Moreover, fair agreement is obtained between an earlier produced computational outcome of the numerical model Delft3D-slurry and analytical solution. This contributes to building confidence in this model as an aid in supporting tailings deposition management.

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“…[6][7][8][9][10][11][12][13][15][16][17][22][23][24][25]28] Attempts to theoretically predict the drag coefficient (and terminal settling velocity) of a sphere moving in a viscoplastic fluid have resulted in several numerical solutions. [16][17][18]28] Various empirical correlations have also been introduced for prediction of terminal settling velocity of a sphere falling in an unbounded viscoplastic fluid.…”

Section: Introductionmentioning

confidence: 99%

“…For many slurries, and especially thickened tailings produced as part of a mine's tailings management or process water recycle operations, the slurry carrier fluid (often < 44 mm particles þ water) exhibits non-Newtonian behaviour. [5,6] In such cases, where the terminal particle settling velocity in a nonNewtonian fluid must be determined, the options are much more limited. [7] The focus of the present study is to provide an improved method to predict the terminal settling velocity of a spherical particle in a non-Newtonian, viscoplastic fluid.…”

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confidence: 98%

Particle terminal settling velocities in non‐Newtonian viscoplastic fluids

Arabi¹,

Sanders²

2016

Can J Chem Eng

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Accurate prediction of the settling velocity of a single particle in a quiescent, non-Newtonian fluid is often required for analysis of fluid-particle systems, e.g. the design and operation of slurry pipelines and solid-liquid separation processes. Wilson et al. presented a direct method that was able to provide reasonable predictions of the terminal settling velocity of a sphere in a fluid with a yield stress. This method is somewhat limited in its applicability: if the fluid yield stress is greater than the calculated reference shear stress, the correlation cannot produce a prediction of terminal settling velocity. Measurements of terminal fall velocities of precision spheres in quiescent Kaolinite-water suspensions were collected in the present study. Kaolinite volume concentrations were 10.6-21.7 % (0.106-0.217 L/L) resulting in suspension yield stresses of 1.3-30 Pa. Both Casson and Bingham models were satisfactory for modelling the clay-water mixture rheology. An analogy of the Wilson-Thomas analysis for the pipe flow of non-Newtonian fluids was used to develop a new method for predicting terminal settling velocity of a sphere in a viscoplastic fluid. The new method does not have the limitations of the Wilson et al. method, and also provides more accurate predictions. The experimental results obtained here show that further research is needed to better characterize particle behaviour at low shear Reynolds numbers (Re Ã < 10).

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Shear cell tests for quantification of tailings segregation

Cited by 11 publications

References 21 publications

Spatial Mapping of Acidity and Geochemical Properties of Oxidized Tailings within the Former Eagle/Telbel Mine Site

Spatial Mapping of Acidity and Geochemical Properties of Oxidized Tailings within the Former Eagle/Telbel Mine Site

Shear settling in laminar open channel flow: analytical solution, measurements and numerical simulation

Particle terminal settling velocities in non‐Newtonian viscoplastic fluids

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